Preparation Of New Functional Polymer Materials And Their Performances In Drug Controlled Delivery

A clay polymer nanocomposite(CPN) based on aspirin-loaded palygorskite(Pal) modified polypyrrole(PPy) was prepared by in situ electropolymerization of pyrrole monomer in the presence of Pal and aspirin. This drug-loading approach was simple and convenient, since colloid templates used in conventional drug-loading system were not needed. The resulting CPN was characterized by TEM, XRD, cyclic voltammetry, electrochemical impedance spectroscopy and FTIR. The CPN was used as a new platform for aspirin delivery, which could significantly enhance aspirin loading capacity of the system and control aspirin release by external electrical stimulus.Biocompatible and three-dimensional hybrids of salicylic acid(SA)-doped PPy and alginate(Alg) were synthesized and employed as a dual-stimuli responsive drug delivery platform. The PPy-Alg hybrids combined the electro-responsive feature of PPy and p H-sensitive feature of Alg. Releasing behaviors of the hybrids using SA as the model drug were investigated at different applied potentials and p H values. Finally, two commonly used mathematical models, Higuchi and Korsmeyer-Peppas models, were employed to understand the release kinetics, respectively, demonstrating that the release is controlled by Fickian diffusion.Dopamine was self-polymerized onto the surface of a glassy carbon electrode(GCE), and the obtained polydopamine(PDOA) functioned as a scaffold for the grafting of half-polyamidoamine(H-PAMAM) dendrimers, which is a new class of polymeric biomaterial as drug carriers. The synthesis of H-PAMAM dendrimers grafted PDOA was characterized by electrochemical impedance spectroscopy, attenuated total reflection infrared spectroscopy, atomic force microscopy, transmission electron microscopy, UV-visible spectroscopy and water contact measurement. Aspirin was chosen as the model drug and loaded into the H-PAMAM dendrimers via ion pairing, hydrogen bonding and hydrophobic interactions. The process of aspirin loading and delivery was also monitored by EIS. The results demonstrated that PDOA films can be used as an excellent platform for grafting of H-PAMAM dendrimers, which is an ideal carrier for drug loading and delivery.